Fluid-pressure device.



G. WESTINGHOUSE.

FLUID PRESSURE DEVIGE. APPLICATION FILED 23.25, 1910. RENEWED NOV. 21912. 1, 1 04,945

a SHEETS-SHEET 1.

Patented July 28 y hkwl w 2 w2 a J2 WITNESSES:

8, MING/ME? G. WESTENGHOUSE.

FLUID PRESSURE DEVICE. APPLIOATIQN FILED 113.26, 1910. RENEWED NOV. 26.1912.-

Patented July 28 INVENIOR G. WBSTENGHOUSH FLUID PRESSURE DEVIUE.

. AIELIOATION FILED P3125, 1910. EEK? EWED 150V. 26, 1912.

Patented July 28, 19M;

3 SEBETS-SHEBT 3.

WITNESS/58:

g aw/MATTUR UNITED STATES-PATENT OFFICE.

GEORGE wnsrmonoosn, or, rxrrssunen; JPENNSYLVANIA, nssrcuon 'ro THEWESTINGHOUSE AIR SPRING COMPANY, A, CORPORATION PENNSYLVANIA.

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Specification of Letters cant.

To all whom it may concern:

Be it known that. I, GEORGE WESTING- HOUSE, a citizen of the UnitedStates, and resident of Pittsburgh, in the county of Al'- legheny andState of Pennsylvania, have invented certain new and useful Improvementsin Fluid-Pressure Devices, of which 'Ih'e'throttlingjeffect at the lowerend of the following is a specification.

My present invention relates to certain improvements in the devices setforth in my prior 'application Serial Number 520,039

filed September 29, 1909. It. resembles said. prior invention insomuchas it is embodied in a fluid compression cylinder particularly adaptedfor use as a compression spring,

which may be used in any relation where. two bodies are so associatedthat resilient movement is desirable, and especially where one or theother of-the bodies is subject to sudden movements, vibrations, orshocks which it is undesirable to have transmitted to the other of' saidbodies.

It will be understood that though capable of use in other relations, theinventionhas been devised primarily in connection with automobiles, andthe general object in View has been to embody the principles ofresilient support by anelastic compression medium, such as air or gas ina practical,"selfcontained, gas-tight compression device adapted toserve all thepur'poses of the steel springs commonly used, and tocombine therewith all the desirable features of. a

shock absorber, the entire devicebeingpassage, so that the flow ofliquid to andv fro between the fixed volume compression space in theupper cylinder and the variable Certain tea tures relating to thepacking and lubrica tion of the sliding joint of the cylinder areapplicable in any relations where high pressures are to be sustained.

The

3 space in the lower cylinder, is more or less throttleda The fluidwithin the cylinder conslsts of a compressible medium such as. air orother gas in the upper portion, and

Patented July 28, 1914. Application filed February 25, 1910, Serial No.-545,854. Renewed November 26, 1912. Serial No. 733,706.

an incompressible, medium, such as oil,

glycerin, -eto., fillingthe lower portion, preferably to a level abovethe packing.

the plunger cylinder -may-, be rendered asymmeric by means of a checkvalve adapted toremain normally open "on thdcomp'iession movement of thespring, but to cut ofi a desired portion of the passage upon theexpansion. movement. 'By locating the valve below the normal level ofthe fluid, all of the fluid which passes to and from the fixed volumecompression space may be subject to the asymmetric throttling actionofthe valve. The normal internal pressure of the fluid medium. ispreferably high, but for convenience in practical operation of anautomobile, is preferably not higher than can be supplied by aneflicient tire pump ofgthe ordinary commercial type.

In my prior application referred to I have shown a pump adapted toremove fluid from'the' low pressure side of the packing for the-slidingjoint betwcenthe cylinder and plunger, and to force the fluid into thepressure cavity within the cylinder. The pump referred to is locatedinside of the cylinder and may be arranged so as to apply a certaindegree of suction between the sliding surfaces of the two cylinders andthismay serve in certain cases to pump air into the cylinder as well asto collect escaping oil. In cases where the pump is of a capacityadapted to produce increase of internal pressure, I may provide anadjustable relief valve adapted to permit escape .of air when theinternal pressure exceeds the .desired value. It will be noted that suchinternal pump operates to cause movement of the fluid by applyingsuction from the inside and whereas equivalent results may be producedby applying pressure from the outside and my present invention includesmeans for externally ap lying suchpressure for such purposes. Theexternal pump which I preferably use for this purpose may be used incombination with an internal pump of the kind described in my priorapplication so that the movement of fluid from his the joint is assistedboth by raising the outside pressure and reducing the inside pressure sothat both suction and forcing cooperate to produce efiicient operationof the device. I

In my present external pump for increasing the external pressure on thelow pressure side of the sliding joint I prefer to utilize thecompression and plunger cylinders as elements of the pump, an exteriorcylinder being rigidly secured to the plunger cylinder so as to form anannular compression space in which the wall of the compression cylinderoperates as an annular piston. \Vhen this external pump is used inconnection with an internal pump the latter may be operated positivelyas set forth in the ap plication of Richard Liebau, Serial No. 15957 ofeven date herewith or it may be operated by flow of the fluid from thevariable volume space to the fixed volume space within the device as setforth in my prior application abovereferred to.

In the drawings Figure 1 is a vertical, axial section through a cylindercontaining my invention. Fig. 2 is a op plan view of the same. Fig. 3 isa view similar to Fig. 1 showing a modified form of outside pump. Fig.4L is a similar view showing the outside pump of Fig. 3 used inconnection with an inside pump such as shown in my prior applicationabove referred to. 4,

The lower cylinder 1 is hermetically closed at the bottom by a screwheadZ and, as shown in Figs. 3 and 4, this head may be formed with adischarge passage 3 which is normally closed by screw plug 4. The eylinder 1 provides the variable space 5 which is adapted to be increased ordecreased by up or down movements of the plunger cylinder 6. The latteris provided on the upper end with a hermetic screw closure 7. As shownin the drawings, the lower end is screw threaded at 8 to a plunger headprovided with an external packing and an internally constricted fluidpassage. The packing con sists of a cup leather 10 clamped against scat11. by means of a flanged annular ring 12. The free edge of the cupleather is 'n-efcrably cut square and is held in close engagement withthe inner walls of the cylindcr by means of a cone 13 which is guided byand longitudinally slidable in 12. The cone is yicldingly held by theaxial spring 14 secured to crossbars 15 and 10 which engage 12 and 13respectively. The plunger is provided with a passage 17 having an intake18 in the sliding joint on the low pressure side of the packing and anoutlet 19 into the device so that when pressure is applied from theoutside pump, fluid may be forced into the compression device duringperiods of high external pressure while reverse flow at other times isprevented by the check valve 20.

The relative movements of thecompression cylinder and plunger cylinderare utilized to produce the pressure required to force fluid through thevalve 20. In the preferred construction I arrange an outer or guardcylinder 22 rigidly connected with plunger cylinder 6 and spaced aparttherefrom so as to form annular compression spaces 23, 24. the upper endof the compression cylinder being-utilized as an annular piston forcompressing the air within either of said spaces. In the form shown inFig. 1 the lower space 2st is utilized for this purpose whereas in theform shown in Figs.'3 and 4 the upper space 23 is utilized.

In Fig. 1, the piston packing for the up per edge of cylinder 1 isprovided by a cup leather 25 clamped between ring 26 screwed to cylinder1 and ring 27 screwed to ring 26. The other end of the compression spaceis closed in by cup leather 28 secured between a ring 29 screwed to thelower end of outer cylinder 22 and a clamping ring 30 screwed to saidring 29. Air may be admitted to this space through any desired form ofcheck valve, and while such valve may be separate as indicated atinFigs. 3 and 4, the leather 28 may be utilized for this purpose by makingthe proportion of parts such that the free edge thereof is held againstthe outer wall of cylinder 1. mainly by resilience of material of theleather and by internal pressure within the space 24.

lVhen in use the pump will be more efficient in proportion to the extentof the expansion and compression movements of the device. For instancewhen used as a spring for an automobile, minor vibrations will producerelatively small compression in the space 24 but in case of a violentcompression air will be drawn into space 2-1 through cup leather 28which will act as a valve to permit entrance of air but to prevent itsescape. Space 24 being thus filled, a violent recoil movement of thespring will cause greatcompression of the air in space 2-l. The pressurethus produced is applied to the sliding joint through passages 30, 30.provided for this purpose and if desired a groove 31 may be provided inthe surface of the plunger cylinder (3 so that passages 30 may dischargethereinto thereby applying the pressure to the inlet 18. .\s it would bediflicult in practice to make the groove 31 to coincide accurately withpassages 30 I prefer to arrange an annular groove 32 about the inside ofcylinder 1 at the level of said inlet passage 30 so thatthc groove 31will come into communication with the pressure in space 24 whenever theexpansion movement is suliicient to bring thc upper end of the groove 31upto the level of 30. Such groove will also serve to a certain ex tentas a collector for surplus oil which will be cl ared therefrom anddriven into groove 31 by the compressed air. It will be understood thata collecting groove may be also formed in the plunger on the level ofinlet 18 and there may be a number of grooves 31.

The arrangements for charging the de vice with oil and compressed airare preferably located in head 7' of cylinder 6. As shown in Fig. 1, aninlet tube 60 extends down a desired distance, so that its outletorifice 61 is at or about the desired level of the liquid to be used.The passage of air or liquid through this tube is controlled by a needlevalve indicated at 62. As indicated in Fig. 2, there is a passage 6stleadingfrom the needle valve chamber to an inlet check valve 65, whichcommunicates with a screw threaded opening 66, to which may be connectedsupply pipes for oil or compressed air. In charging the device oil maybe introduced by loosening needle valve ,6). and supplying oil throughopening (36 and check valve (35. After oil has been charged into thedevice to or above the level of the orifice ()1 of pipe v60, thecompressed air is introduced through 66, 65, 64, 60, until the internalpressure is sufiicient to support the desired load with the partsapproximately in the position indicated in Fig. 1. The air supply isthen detached and surplus oil blown out through the pipe 60. The plugvalve 62 and the plug 67 are then screwed tight and the device is incondition for use. Undue raise of pressure may be prevented by anautomatic relief valve, which is diagrammatically indicated in Fig. 2 ascomprising a plug valve 70, closing springt'l, and screw adjusting means72 for adjusting the initial pressure of the spring to therebypredetermine the maximum internal pressure in the device. The liquidused is preferably pure, free flowing, mineral oil, and

it may be mixed with pure, perfectly pulverized graphite.

The above described device is provided at both ends with journals 80,80, adapted to engage pivots of a universal joint comprising pivotsarranged at right angles to each other and a cooperating bracketattached to one of the members to be cushioned by said device.

As stated above the space 23 may also be utilized for compressionpurposes and arrangements suitable for this purpose are shown in Figs. 3and 4c in which the packing for the piston consists of a cup leather 35hearing against the outer cylinder 22 and clamped between a screw ring36, screwed on to the upper end of cylinder 1 and a clamping ring 37screwed to ring 36.

An inlet check valve conventionally indicated at 40 is arranged on thecylinderhead 7. \Vith this arrangement expansive movements of the springserve to draw in air through the check valve, while return movementcompresses it, and when the movement is sufficie at to produce asufiicient compression the escapes downward through the joint betweenthe piston head 36 and the adjacent wall of cylinder 1. This raises thepressure on the rear side of the sliding joint thereby tending to forceoil or air or both upward through the valve 20. As the fit of thesliding joint is usually very perfect I prefer to provide the outersurface ofcylinder 6 with one or more vertical grooves 41, 42,communicating with a circumferential groove arranged at the level of theintake 18.

In normal operation of the device when used for instance as a springsupport on an automobile, the pump piston'being a part of the lowercylinder, the pumping movements will be greater and more efiicientaccording as the device as a Whole is subject to greater compression andexpansion. For instance, vhen the automobiles passes over a sutlicientlyhigh obstruction at suflicient speed the relative movement will carrythe pump piston through the extreme range of the expelling stroke andthe air in space 23 will be enormously compressed thereby driving oil orair through grooves 41, 42, inlet 18, valve 20 and through the discharge19 into the interior of the device. Lesser movements of the spring willbe proportionately less efficient and some of them will, be insuf--ficient to produce sufficient pressure to operate the valve against thegreater internal pressure. It will be found, however, that the greatpower and long stroke of the pump render it so eflicient that asatisfactory amount of pumping operation may be produced even where theextreme movements occur only at considerable intervals.

The above described form .of external pump for applying pressure to thejoint in the rear of the packing is particularly useful when combinedwith any of the internal pumps set forth in the applicationshereinbefore referred to. A. particular instance of this is shown inFig. 4 wherein all the parts of the external pump are exactly as in Fig.3, while the plunger, collecting groove packing and internal pump aresubstantially the same as in my prior application Serial No. 520,039.

Both pumps compress on the compression stroke of the device as a wholebut the external pump has a stroke determined by the extent of thecompression and expansion of the device while the internal pump has arelatively short stroke dependent on the violence of flow of the fluidto and fro between the variable and fixed volume compression spaces. Thesignificant relation of the two pumps is that the external pump suppliescompressed air to the annular collecting groove and inletvalve of theinternal pump so that the latter mav be assisted by the externalpressure. The relation is similar where my external pump is used withany other form of internal pump such for instance as is shown in variousapplications filed by me or by Richard Liebau.

As before stated the internal pump shown in Fig. 4 forms-the subject ofmy prior application and is claimed herein only in combination with theexternal pump. It is nevertheless desirable to briefly describe itsoperation.

The annular groove 181 corresponds to the groove 31 of Fig. 1 whilevalve 120 corresponds to the valve 20 of Fig. 1 but the outlet fromvalve 120 leads to the pump cavity 121 and thence through valve 122 andoutlet 123 to the interior of the device.

The pump plunger 180 is arranged to per-- which latter is preferablyformed integral with the pump stem. Thai-movements of the pump stem areforced by means of the disk valve 127 arranged in the path of the flowof fluid from the variable space 5into the fixed volume space in theupper cylinder. This disk is loosely mounted on the piston stem so as toplay freely between the annular enlargement 126 and the check nut 128.In operation expansion of the device causes downward movement ofthefiuid and disk which carries with it the pum piston. Compressionmovement of the device causes reverse flow of the fluid forcing the diskin the opposite direction thereby forcing the plunger to the end of theexpelling stroke. The power of the movements of disk 127 in response tofluid flow may be increased by arranging a construction 129 midway ofthe path of movement. It will be noted that the resistance offered toupward flow of fluid when the parts are in the position shown in Fig. 4is relatively small whereas downward flow carrying the valve down to andseating it upon 130 very greatly constricts the area available forpassage of the liquid. The object of this arrangement is to permitrelatively free compression of the spring as a whole and to partiallythrottle the return movement to prevent the disagreeable recoil which isfrequently attendant upon the operation of vehicle springs when notprovided with recoil preventing devices.

Various features of my invention are adapted for use in other relationswhere the conditions and functions to be served are similar, as, forinstance, in other devices wherein a sliding joint is required tosustain great pressures without leaking; also they may be used as asupplementto or substitute for and may be supplemented or substituted byfeatures set forth in the application of Richard Liebau, Serial No.468,762,

filed December 22nd, 1908.

While I have herein fully shown and described and have pointed out inthe appended claims certain novel features of construction, arrangement,and operation which characterize my invention, it will be understood bythose skilled in the art that various omissions, substitutions, andchanges in the forms, proportions, sizes, and details of the device andof its operation, may be made without departing from my invention.

I claim: I

1. An elastic compression device, comprising relatively movable membersfor varying the volume of the elastic fluid contained in said device, incombination with a pump having a cylinder mechanically connected withone of said movable members and a piston mechanically connected with theother of said members and arranged to increase the pressure on the lowpressure side of the sliding joint between said members.

2. An elastic compression device, comprising relatively movable membersfor varying the volume of the elastic fluid contained in said device, incombination with an external pump having a cylinder mechanicallyconnected with one of said movable members and a piston mechanicallyconnected with the other of said members and arranged to increase thepressure within the pressure cavity of said device.

3. An elastic compression device, comprising a cylinder and a plungeradapted for relative movement to vary the volume of the elastic fluidcontained in said device, in combination with a pump having a cylindercarried by the plunger and a piston mechanically connected with saidcylinder and arranged to increase the pressure within the pressurecavity of said device, upon the proper relative movement of saidcylinder and plunger.

4. An elastic compression device, comprising a cylinder and a plungeradapted for relative movement to vary the volume of the elastic fluidcontained in said device, in combination with an external pump having awall formed by a cylinder concentric with and carried by the plunger anda piston carried by the wall of said cylinder, said pump being arrangedto increase the pressure within the pressure cavity of said device.

5. An elastic compression device, comprising relatively movable membersfor varying the volume of the elastic fluidcontained in said device, incombination with a pump havinga compression cavity carried by one ofsaid movable members and a piston mechanically connected with the otherof said members and arranged to discharge fluid at high pressure withinthe pressure cavity of said device.

compression cavity carried by said plunger and'a piston having-a strokeequal to and caused by the relative movements of said plunger andcylinder, said pump being arranged to apply pressure to the slidingjoint between said plunger and cylinder; together with an internal pumparranged to apply suction to said sliding joint and. to discharge withinthe pressure cavityof said device, any fluid removed from said joint.

7 An elastic compression device, comprising a cylinder, a plungermovable relative thereto for varying the volume of the elastic fluidcontained in said device, said cylinder and plunger being connected by asliding joint, in combination with means providing a passage from thelow pressure side of the sliding joint to a pressure within the device,an inlet valve controlling said passage, and an external pump concentricwith said cylinder and arranged to apply pressure to the said passage.

8. An elastic compression device, comprising relatively movable membersfor varying the'volume of the elastic fluid contained in said device, incombination with a pump having a compression cavity carried by one ofsaid movable members and a piston connected with the other of saidmembers so as to have a positive stroke approximately equal to thedistance of relative movement of the relatively movable parts of thecompression device, said pump being arranged to increase the pressurewithin the pressure cavity of said device.

9. An elastic compression device, comprising relatively movable membersfor varying the volume of the elastic fluid contained in said device, incombination with a pumphaving a cylinder mechanically connected with oneof said movable members and a piston connected with the other of saidmembers so as to have apositive stroke approximately equal to thedistance of relative movement of the relatively movable parts of thecompression device, said pump being arranged to increase the pressurewithin the pressure cavity of said device.

10. An elastic compression device, comprising a cylinder and a plungeradapted for relative movement to vary the volume f the elastic fluidcontained in said device, in combination with an external pump having acylinder carried by the plunger and a piston connected with saidcylinder so as to have a positive stroke approximately equal to thedistance of relative'movement of the relatively movable parts of thecompression device, said pump being arranged to increase the pressurewithin the pressure cavity of said device.

11. An elastic compression device, comprising a cylinder and a plungeradapted for relative movement to vary the volume of the elastic fluidcontained in said device, in combination with an external pump having anannular compression space carried by the,

plunger and a piston formed upon the upper edgeof said cylinder, saidpump being arranged to increase the pressure within the pressure cavityof said device.

12. An elastic compression device, comprising relatively movable membersfor varying the volume'of the elastic fluid contained in said device, incombination with a pump hav ing a cylinder rigidly connected'with one ofsaid movable members and a piston connected with the otherof'saidmembers so as to have a positive stroke approximately equalrelative movement to ary the volume of the elastic fluid contained insaid device, in combmation with an external pump havlng a compressionchamber carried by the plunger and a piston connected with said cylinderso as to have a positive stroke approximately equal to the distance ofrelative movement of the relatively movable parts of the compressiondevice, said pump being arranged to remove fluid from the low pressureside of the joint between the plunger and cylinder.

14. An elastic compression device, comprising relatively movable membersfor varying the volume of the elastic fluid contained in said device, incombination with an internal pump having a cylinder carried by one ofsaid movable members and a piston operated by flow of fluid within thedevice, arranged to receive fluid'from the low pressure side of thejoint between said movable members and to discharge fluid at highpressure within the pressure cavity of said device, together with anexternal pump arranged to apply pressure to the low pressure side ofsaid joint.

15. An elastic compression device, comprising a cylinder and a plungermovable relatively thereto for varying the volume of the elastic fluidcontained in said device, in combination with an internal pump having acylinder mounted upon said plunger and a piston operated by flow offluid within the device, said pump being arranged to take in fluid fromthe low pressure side of the plungerjoint and to discharge fluid underhigh pressure into the pressure cavity within said device; together withan external pump arranged to apply pressure to the intake of said firstmentioned pump.

16. An elastic compression device, comprising a c linder and a plungermovable relatively t ereto for varying the volume of the elastic fluidcontained in said device, in combination with an internal ump having acylinder mounted uponsaid plunger and a piston operated by and inaccordance with relative movement of said cylinder and plunger, saidpump being arranged to take in fluid from the low pressure side of theplunger joint-and to discharge the same so as to increase the pressurewithin the pres sure cavity of said device; together with an externalpump concentric with said cylinder and arranged to apply pressure to theintake of said first mentioned pump.

17. An elastic compression device, comprising a com ression cylinder anda plunger cylinder a apted for relative movement to vary the volume ofthe elastic fluid contained in said device, an internal pump having acompression chamber carried by the.

plunger and a piston operated non-positively by the compression andexpansion movements of said cylinder and plunger so as to have a strokemuch less than the distance of relative movement of the relativelymovable parts of the compression device, said pump being arranged toincrease the pressure within the pressure cavity of said device, incombination with an exterior compression pump arranged to increase thepressure at the intake of said internal pumdp, said pump comprising anexterior cylin er carried by said plunger cylinder and forming therewithan annular compression space for which the wall of said compressioncylinder forms an annular piston.

18. An elastic compression device, comprising a compression cylinder anda plunger cylinder adapted for relative movement to vary the volume ofthe elastic fluid contained in said device an internal pump having acylinder carried by the plunger, and a piston operated by a valve diskhaving a loose mechanical connection with the stem of said piston, saidpump being arranged to receive fluid from the low pressure side of thesliding joint between said compression and plunger cylinders, incombination with an exterior compression pump arranged to supplypressure at said low pressure side of said sliding joint, said exteriorpump comprising an exterior cylinder carried by said plunger cylinderand forming therewith an annular compression space for which the wall ofsaid compression cylinder forms an annular piston.

19. An elastic compression device, comprising a cylinder and a plungeradapted for relative movement to vary the volume of the elastic fluidcontained in said device, in

combination With an external pump having a cylinder carried by theplunger and .a iston mechanically connected with said plunger andarranged to increase the pressure, within the pressure cavity of saiddevice.

20. A cushion device comprising a cylinder, a plunger fitted to slidetherein to permit variation of the volumetric capacity thereof, apacking for the sliding joint between said cylinder and plunger, a pumpfor supplying pressure to the sliding joint on the low pressure side ofsaid packing and a second pump for transferring fluid from said slidingjoint to the interior of said cylinder.

21. A cushion device comprising relatively movable members forming achamber and having a sliding joint therebetween to permit variation ofthe volumetric capacity thereof, in combination with two pumps, onearranged to supply fluid under pressure to said sliding joint, and theother arranged to transfer fluid from said sliding joint to saidchamber, and a check valve in the path of flow of the fluid to saidlatter pump, said check valve being arranged to admit and retain fluidflowing toward said latter pump.

22. A cushion device comprising telescopically arranged cylinders havinga packed sliding joint therebetween to permit variation of thevolumetric capacity of the chamber formed thereby, in combination withtwo pumps, one arranged to supply fluid under pressure to the lowpressure side of said packed joint, and the other to transfer fluid fromthe low pressure side of said packed joint into said chamber.

23. A cushion device comprising telescopically arranged cylindersforming a cushion chamber, a packing for the sliding joint therebetween,a guard cylinder and a check valve cooperating With said guard cylinderand one of said telescopically arranged cylinders to form a valved pumpfor supplying fluid under pressure to said chamber.

24. In an air spring, telescopically-arranged cylinders forming a closedchamber having a sliding joint, a packing for said joint, a guardcylinder surrounding said members and serving as a collecting chamberfor the liquid which leaks past said packing, and an inlet passage fromsaid guard cylinder to said closed chamber.

25. In an air spring, telescopically-arranged cylinders forming a closedchamber having a sliding joint, a packing for said joint, a guardcylinder surrounding said members and serving as a collecting chamherfor the liquid which leaks past said packing, an inlet passage, andmeans for transferring leaked liquid from said collecting chamber tosaid closed chamber.

26. In an air spring, telescopically-arranged cylinders forming a closedchamber having. a sliding joint, a packing for said joint, a guardcylinder surrounding said members and serving as a collecting chambertor the liquid which leaks past said packing, an inlet. passage, andmeans operating upon the relative movement of saidtelescopically-arranged members for transferring leaked liquid from saidcollecting chamber to said closed chamber.

27. In an air spring, three concentric cylinders one of which isarranged to telescope between the other-two forming an interior closedchamber and a collecting chamber for leaked liquid, a passage. from saidcol lecting chamber to said closed chamber, and means operating upon thetelescopic movement of said cylinders to transfer liquid from saidcollecting chamber to said interior chamber.

28. A cushioning device comprising telescopically arranged 'cylindricalmembers forming a closed chamber, a packing for the joint between saidmembers, a guard cylinder surrounding said members, a packing betweensaid guard cylinder and one of said members, and a valve controllingdelivery through a passage communicating with an annular space inclosedby said guard cylinder and the chamber inclosed by said telescopingmembers.

29. A cushioning device comprising telescopically arranged cylindricalmembers, forming a closed chamber, a packing for the joint between saidmembers, a guard cylinder surrounding said members, and a valve forcontrolling delivery through a passage communicating with the chamberinclosed by said members, and an annular chamber formed between saidmembers and said guard cylinder.

30. A cushioning device comprising relatively movable telescopicallyarranged cylindrical members inclosing a chamber and having a slidingjoint thcrebetween to permit of variations in the volumetric capacity ofsaid chamber, a packing for the joint, a guard cylinder surrounding theoverlapping edges of said members, packings located between said guardcylinder and one oi said members, and inclosing an annular chamberbetween the guard cylinder and the member, and a passage around saidfirst mentioned packing nular chamber said members.

31. A cushioning device comprising relatively movable telescopicallyarranged cylindrical members having a sliding joint therebetween andinclosing a chamber, a packing for said joint, a guard cylindersurrounding and the chamber inclosed by and communicating with said an-,

said members, two relativelymovable annular packings between said guardcylinder and one of said members, and a valve controlling deliverythrough a passage communicating with the chamber inclosed by saidmembers and the annular chamber inclosed by said annular packings andsaid guard cylinder.

32. A cushioning device comprising relatively movable members forming achamber and having a sliding joint therebetween to permit variations inthe volumetric capacity of the chamber, a guard member surrounding saidrelatively movable members and extending beyond the overlapping edgesthereof and forming with said members a second chamber partiallysurrounding the first mentioned chamber and having a means ofcommunication through said relatively movable members with said firstmentioned chamber. and a packing for the joint between said relativelymovable members.

33. A cushioning device comprising relatively movable members inclo'singa chamber and having a sliding joint therebetween to permit ofvariations in the volumetric capacity of the chamber, a packing for saidsliding joint, a guard member surrounding said relatively movablemembers and extending beyond their overlapping edges. and a valvecontrolling delivery through a passage formed in said relatively movablemembers on the low pressure side of the packing. and establishingcommunication between the chamber inclosed by said members and the spacesurrounded by said guard member.

34. A cushioning device comprising telescopically arranged cylindricalmembers inclosing an interior chamber and having a sliding jointtherebetween to permit variations in the volumetric capacity of saidchamber, a guard cylinder surrounding said members and overlapping thejoint between them and forming an exterior chamber around the members, acheck valve for controlling delivery into said interior chamber througha passage formed in said members and communicating with the exteriorchamher, and a packing for the sliding joint between said members andfor preventing leakage from the interior chamber.

Signed at New York city in the county of New York and State of New Yorkthis Q-lth day of February, A. D. 1910.

GEO. WESTINGHOUSE.

Vitnesses RICHARD Lmnan, IRVING M. Onnnzerrr.

